I recently started bringing my son to school, it's all back roads and only about 3 miles away. I had reset the fuel economy gauge and it's only reading mpg of about 11.4 max. I'm very light on the pedal and I'm not carrying any extra cargo other than myself and my son.
The only thing that's not "usual" is that the tonneau cover is off.

Now according to the original sticker it should be getting 14 city 18 highway.
But I'm getting about the same mpg(slightly more) as I get with my 2500 burb with a 7.4l engine.

Something just seems not right. There's no check engine light, it seems to idle and accel properly, no flat spots etc. It does have about 75k miles on it, and it's just recently indicated that it's due for an oil change.

So the best numbers it's gotten are 11.4 city, and 14.6 highway. But I can't really say the conditions for the highway driving since it's my wife who's usually driving it on the highway. From experience she's kind of heavy on the pedal when she drives so I'm not sure that the highway mpg is a true reflection of the best possible number.

I had to drive my Buddies when i was in Ga for about a month when my Chevy ate the tranny. I got about 16 driving to work which was back roads about 55mph. and it only got about 17.5 driving to Atlanta straight highway. I never really did any straight city so no real clue but i would have thought right in line with your number since i drive pretty hard in town.

Well your Avi is all stock isnt? I mean your not running huge offroad tires etc? because on my 06 i lost 2mpg (not kidding either i was ticked) when i switched to the Goodyear Wrangler Silent Armors (kevlar and HEAVY!) after i switched to Duellers i got 1.5Mpg back from the OEM and junk tires..

Thats the right size.. And those AT/S arent that heavy i just picked up a set for my 2000 Z71 and they seemed lighter than the tires that were on it.. Hmmm mabey its time for a tune up a little early...

Did an oil change Saturday. Since the oil change I've only driven today on the usual route (Drive my son to school and come back home), and noticed the mpg creep up a little to 11.6mpg from 11.4.
I didn't reset the mpg so it may be showing a slower increase due to previous miles driven/recorded. I'll reset it tomorrow and see what it does.